The United Nations will call on Monday for 2% of worldwide income to be invested in the green economy, a move it says would boost jobs and economic growth.

The call is expected to be matched by statements of support for low-carbon investment from heads of state including President Barack Obama of the US and Hu Jintao of China, and several chiefs of multinational companies.

An investment of 2% of global GDP would more than pay for itself in the form of millions of new jobs, the development of new industries, health benefits from cleaner air, energy efficiency savings and a reduction in greenhouse gas emissions, the UN is expected to say.

These findings are also backed up by a report to be published today by the German government, which warns that Europe will suffer continued low growth rates unless investment in green projects is increased. Raising the level of ambition in the EU's climate targets would increase European GDP by up to $842bn, a 6% rise, and create up to 6m additional jobs across member states.

In the US, investment in renewable energy has stalled, and an HSBC analysis found that Republican plans currently before Congress would more than halve federal spending on low-carbon projects, including high-speed rail, carbon regulation and contributions to international climate funds. Plans put forward by Obama, by contrast, provide for a 20% increase in climate and clean energy funding above 2010 levels, paid for by the repeal of $4bn in fossil fuel subsidies and research.

Nick Robins, head of climate change at HSBC, said: "We expect tough negotiations to close this gulf in budgetary priorities between the president and Congress... Although we do not expect all the proposed cuts to materialise, key climate initiatives look set to be curbed."

The German environment ministry's report, also seen by the Guardian, added to this case, concluding that the current 20% target "has become too weak to mobilise innovations". Sticking with it, the authors say, "is the equivalent of digging deeper while still being stuck in a hole", while the 30% target is not only achievable but "economically beneficial".

In the UK, a group of leading businesses will unite today to urge George Osborne, the chancellor, to include measures to stimulate low-carbon development in his March Budget. Peter Young, chairman of the Aldersgate Group, said: "The chancellor has promised a budget for growth but we believe this must be a budget for green growth. The UK needs an explicit strategy to take advantage of the global shift to a green economy, driving jobs and exports. Cuts alone will not deliver a competitive economy."